Air tool

ABSTRACT

An improved air tool includes an integrated air motor and electrical generator wherein the stator is positioned on a side of the rotor body opposite the working end of the tool to reduce vibrations transmitted to the stator. The stator is also positioned between the compressed air inlet and the rotor body such that compressed air flows across the stator to prevent overheating of the stator. The air tool includes an indicating circuit connected to the battery charging circuit for indicating a battery charge condition, a battery discharge condition, and a low lubrication condition of the air vanes. A light ring assembly is attached to the working end of the tool housing to provide light at the working end of the tool. Materials chosen for the magnets and the poles of the stator increase the power capability of the electrical generator. An illuminating apparatus for a conventional air tool includes a light ring with integral generator.

This application is a continuation of application Ser. No. 08/353,244,filed Dec. 2, 1994 now U.S. Pat. No. 5,525,842.

BACKGROUND OF THE INVENTION

The present invention relates in general to improvements to air poweredtools and, in particular, to improvements to air powered tools that havean air motor having an integral generator (integrated air motorgenerator or IAMG).

An air tool with an air motor having an integral generator is disclosedin U.S. Pat. No. 4,678,922 issued on Jul. 7, 1987 to the inventor of thepresent invention. U.S. Pat. No. 4,678,922 is hereby incorporated byreference. FIG. 12 shows the side-pole arrangement of the air motor andintegral generator of the '922 patent. As shown in FIG. 12, theside-pole arrangement includes a bearing 139 at the working end of thetool, a bearing end plate 178, an insulating ring 142, coils 180, amagnet rotor 174 having magnets 176, an air chamber 134, a rotor shaft146, a rotor body 148, fins 150, a bearing end plate 142, a bearing 154and a retaining ring 156.

In the side-pole arrangement of FIG. 12, the magnet rotor 174 and coils180 are positioned between the working end of the air tool and the rotorbody 148. In such a position, it has been found that the magnet rotor174 and coils 180 are subjected to a large amount of vibrationstransmitted from the working end of the tool. These vibrations arefreely transmitted directly to the permanent magnets 176 in the magnetrotor 174 thereby causing detrimental changes in the magnetic properties(magnetic disorientation) over time. This magnetic disorientationresults in diminished energy from the magnetic circuit and consequentdiminished electrical output from the generator.

Another problem associated with the prior art side-pole arrangement isoverheating of the coils 180. Overheating of the coils 180 causes thespecific resistance of the current carrying conductors (wire) comprisingthe coils to increase thereby diminishing the electrical output of thegenerator.

FIG. 13 shows a prior art air tool 310 having rechargeable batteries332, a handle 326, an air motor 318, a shaft 320, a casing 314, a disc322, a lever 324, an air hose 312, an air hose fitting 316, a gooseneck330 and a lamp 328.

A problem with the air tool of FIG. 13 is that the gooseneck lamp 330,328 must be frequently adjusted to provide adequate lighting to the worksurface. The gooseneck lamp 330, 328 also undesirably adds to theoverall exterior dimensions of the air tool 310 thereby making it moredifficult to work in cramped areas.

There has also been a need to provide smaller air tools which cangenerate the same amount of or more electricity than a larger tool.Smaller tools are desirable for working in smaller areas and forreducing the amount of materials required for manufacture of the tool.Increased power capability is desirable to provide better lighting andto enable other electrically driven devices to be powered by theintegral air motor generator.

Another problem with the prior art air motors with integral generatorsis determining whether or not the generator is functioning properly.That is, if the generator malfunctions and power begins to be drawn fromthe batteries, it is desirable to know that the generator ismalfunctioning prior to complete discharge of the batteries andcensequent total loss of electric power.

Still another problem with the prior art is determining when the movableair vanes 150 (FIG. 12) are not adequately lubricated. Inadequatelubrication of the vanes 150 results in excessive wear to components ofthe motor, decreased power output and possible seizing of the motor.Therefore, it is desirable to have an indication of the lack of adequatelubrication prior to any damage to the tool.

A problem with air tools that do not have an integrated generator isthat of providing adequate lighting to the work area. Battery packs orseparate lighting devices are heavy in weight and increase the number ofseparate items that must be transported to a work area.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved air toolwherein the integrated generator is subjected to less vibration.

It is another object of the present invention to provide an improved airtool wherein the integrated generator operates in a cooler environment.

It is yet another object of the present invention to provide an improvedair tool with an integrated lighting device which is light in weight,automatically directed towards the working area and is small in size.

It is a further object of the invention to provide an improved air toolwhich can be made smaller in size.

It is still another object of the present invention to provide animproved air tool with increased electrical power capability.

It is yet another object of the present invention to provide an improvedair tool which can indicate whether or not the generator is charging.

It is yet a further object of the present invention to provide animproved air tool which indicates whether or not lubrication to the airvanes is sufficient.

Another object of the present invention is to provide an illuminatingapparatus with an integrated electric generator for providing light to aconventional air powered tool.

These and other objects of the present invention are achieved by an airtool having a working end and comprising a tool housing; a compressedair inlet; and an integrated air motor and electrical generator, forpowering the air tool and positioned within the housing, the integratedair motor and electrical generator including a shaft mounted on abearing, for rotation within the housing; a rotor body attached to theshaft; a plurality of vanes connected to the rotor body; a plurality ofmagnetic elements disposed in the rotor body; and a stator positionedwithin the housing axially aligned with the rotor body, on a side of therotor body opposite the working end of the air tool and between thecompressed air inlet and the rotor boy such that compressed air flowsacross the stator, wherein the stator interacts with the magneticelements to generate electricity when the rotor body is rotated by thecompressed air.

Preferably, the bearing on which the shaft is mounted is positioned on aside of the rotor body adjacent the working end of the tool and theshaft does not extend beyond the opposite side of the rotor body.

Advantageously, the stator includes a stator housing and the air toolfurther comprises a rotor collar disposed on the shaft on a side of therotor body adjacent the working end of the tool, for maintaining adesired gap between the side of the rotor body opposite the working endof the tool and the stator housing.

Another aspect of the invention includes an air tool having a workingend and comprising a tool housing; a compressed air inlet; an integratedair motor and electrical generator, for powering the tool and positionedwithin the housing, the integrated air motor and electrical generatorincluding a shaft mounted on a bearing, for rotation within the housing;a rotor body attached to the shaft; a plurality of vanes connected tothe rotor body; a plurality of magnetic elements disposed in the rotorbody; an air cylinder made of a nonmagnetic material and surrounding theplurality of vanes; and a stator positioned within the housing axiallyaligned with the rotor body, wherein the stator interacts with themagnetic elements to generate electricity when the rotor body is rotatedby the compressed air and wherein the air tool further comprises abattery charging circuit and a battery connected to the stator; and anindicating circuit connected to the battery charging circuit forindicating a battery charge condition, a battery discharge condition,and a low lubrication condition.

Preferably, the indicating circuit includes a resistance temperaturedetector bridge comprising a thermistor disposed in the vicinity of theair cylinder and responsive to a temperature of a cylinder wall and athermistor responsive to a temperature of the compressed air.

In a preferred embodiment, the air tool includes a light ring assemblyattached to the tool housing to provide light at the working end of thetool.

One embodiment of the light ring assembly includes a generallycylindrical retainer ring having open ends and connected to the toolhousing; an annular lens disposed in the retainer ring at an endfurthest from the tool housing; an annular reflector having a pluralityof openings formed therein and disposed adjacent the lens; and anannular ring having a plurality of lamps that are inserted in theopenings of the annular reflector wherein the lamps are electricallyconnected to the stator.

Another embodiment of the light ring assembly includes a lampelectrically connected to the stator; and a plurality of optical fibershaving first ends optically coupled to the lamp and second ends thatterminate in a circular array at the working end of the tool.

The present invention also includes an illuminating apparatus for apower tool having a spindle and a tool housing, the illuminatingapparatus comprising a housing having first and second ends; a lensdisposed at the first end of the housing; a lamp disposed behind thelens; a reflector surrounding the lamp and including a coil connected tothe lamp; and a rotor including a magnetic element wherein the rotor isattachable to the spindle and is disposed adjacent the coil wherebyrotation of the rotor induces electromotive force in the coil andwherein the second end of the housing includes a retaining ring forattachment to the tool housing.

These and other objects, features and advantages of the presentinvention will become apparent from the following detailed descriptiontaken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are hereby expressly made a part of the specification.

FIG. 1 is a perspective view of a cantilever rotor shaft showing thesidepole integration of magnetic circuit elements;

FIG. 2 is a perspective view of a four pole generator stator coreshowing the coil form and coils and their positioning with respect tothe core;

FIG. 3 is an exploded perspective view of an improved IAMG statorassembly showing the core with coils mounted, electrical connections andhousing;

FIG. 4 is a composite multidimensional view of the stator in itsassembled form;

FIG. 5 is an exploded view of an IAMG showing the relative positioningof each of its components;

FIG. 6 is a transverse cutaway view of the interior of an air toolshowing the air inlet, throttle mechanism, block diagram of batterycharging and indicator LED circuit, generator stator, cantilever rotorwith air vanes, front bearing supports, PTO (power take off), batterycells, electrical contacts and housing;

FIG. 7 is a transverse cutaway view of the exterior housing of an airtool having an integrated light ring appliance;

FIG. 8 is a transverse sectional view of a complete air tool having anintegrated light ring appliance;

FIG. 9 is an exploded perspective view of a light ring appliance;

FIG. 10 is a multidimensional view of a tool light ring assembled inrelation to a keyless drill chuck of clear plastic which can allow lightto pass through to the drilling surface;

FIG. 11 is a partial transverse cutaway view of the front portion of ahigh speed tool showing an integrated light ring generator attached tothe tool;

FIG. 12 shows a prior art side-pole air motor with integral generator;and

FIG. 13 shows a prior art gooseneck lamp on an air tool;

FIG. 14A is an exploded view of another embodiment of a stator assembly;

FIG. 14B shows the stator assembly of FIG. 14A assembled;

FIG. 15A shows the stator of FIG. 14B in an air tool with the housingpartially cutaway;

FIG. 15B shows a tool cover for the air tool of FIG. 15A with the toolcover partially cutaway;

FIG. 15C shows the tool cover of FIG. 15B mounted on the tool of FIG.15A;

FIG. 16 shows another embodiment of an air tool having a stator similarto that of FIG. 14B;

FIG. 17 schematically shows an optical fiber light ring arrangement; and

FIG. 18 schematically shows another optical fiber light ringarrangement.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An integral air motor generator (IAMG) converts compressed air intorotary torque and electricity. The inventive IAMG utilizes an improvedsidepole stator and rotor arrangement.

FIG. 1 shows a modified rotor body 50 referred to as a cantilever rotor.The cantilever rotor design improves magnetic induction and decreasesthe required amount of space, thereby allowing the incorporation of theIAMG into small air powered tools. Significantly improved magneticinduction in the electromagnetic circuit of the generator has beenachieved through the incorporation of the magnetic elements 51 into theair motor rotor body 50 (or a segment of the same) in a sidepolearrangement as shown and utilizing nonmagnetic material for the shaft 53and rotor body 50 (such as stainless steel carbon fiber reinforcedthermoplastic or glass fiber reinforced thermoplastic).

An improved permanent magnet 51 is made of a metallic compoundconsisting of the element neodymium (Symbol Nd, Atomic number, 60,Atomic weight, 144.27) mixed with iron and boron (NdFeB), wherebyreplacing magnets of ceramic or cobalt. The utilization of the NdFeBmaterial raises the average magnetic flux density in the electromagneticcircuit from about 27 mega gauss (MG), the maximum average in priorgenerator embodiments utilizing Samarium Cobalt, to about 38 MG with amaximum level of about 42.5 MG. The increased magnetic flux densityproportionally increases the emf generated in the generator's statorcoils.

Again referring to FIG. 1, the amount of space required for the IAMG hasbeen reduced by eliminating the axial rear support portion of the shaftthat would be located at 52 and also eliminating the rear alignmentbearing 154 and end plate 152 (see FIG. 12), thereby making room for thegenerator stator at the rear of the tool. A second alignment bearing isthen positioned on the shaft's opposing (front) end at 53.

The cantilever rotor arrangement is not necessary when working with aconventional rotor shaft over one inch in diameter. In this case, therear bearing can be set directly into the core of the generator's statorwith a bore through the center of the core and stator housing to allowfor the alignment of a conventional shaft. A bearing comprising magneticmaterial positioned as described has no detrimental effect on theconducting of magnetic flux through the core path.

FIG. 2 shows a side (four) pole stator core generally at 54, coil from55 and coil 56. The stator core 54 has a ring or toroidial baseconfiguration 54a with an even number of poles 57 which support plasticcoil forms 55 with copper windings forming the coils 56. The poles 57with coils 56 are positioned equidistant from each other such that thefaces of each pole 57 line up with the faces of the magnets 51 in therotor shaft 50 of FIG. 1. The object of the alignment is so that themagnetic flux is, for practical purposes, entirely within the corematerial as the magnets line up with the top of the poles, so thatinteraction with nearby components is minimized and also so that theflux follows a desired path through the center of the coils.

The core 54 may be made of a high-permeability magnetic alloy referredto as Hiperco 50A Permendur 49 containing 49.4 percent of cobalt(Symbol, Co, Atomic number, 27, Atomic Weight 58.94), 1.94 percentvanadium (Symbol, V, Atomic number, 23, Atomic weight, 50.95) with thebalance iron. Another alloy with similar magnetic properties has alsobeen practiced, which alloy is referred to in the trade as Alloy 4750containing 47.56 percent nickel (Symbol, Ni, Atomic number, 28, Atomicweight 58.71) with the balance iron. These materials at their highestmagnetic saturation exhibit a magnetic flux density near 1.2×10000 gaussor 1.2 teslas and have a low hysteresis loss. The above alloys wereselected because they are capable of conducting magnetic flux direction(N/S) changes exceeding frequencies of 1000 Hz, which are necessary dueto the rotational velocity of the rotor shaft's magnetic circuitassembly which may exceed 30,000 rpm.

Improved electrical induction has also been accomplished by utilizingcoil windings 56 made of 100 percent copper (Symbol, Cu, Atomic number29, Atomic weight, 63.54) and having coil forms 55 with minimal insidewall thickness (approx. 0.010 inch).

FIG. 3 shows an exploded perspective view of the components comprisingthe generator stator designated generally as 58. Included are the coreand coil assembly 59, coil lead wires with positive circuit contact 60,coil lead wires with negative circuit contact 61, positive front statorhousing 62, nonconductive spacer 63, and negative rear stator housing64. FIG. 4 is a composite multidimensional view of the assembled statorand FIG. 5 is an exploded view of the IAMG showing the relativepositions of the rotor 50, magnets 51 and stator 58 with the othercomponents of the air motor.

Improved operating efficiency has been maintained for extended periodsby positioning the generator stator 58 and corresponding rotor bodymagnetic elements 51 at the air inlet end of the air motor and,preferably, by further providing rubber or plastic damping sleeves 51Asurrounding the magnets 51, thereby isolating the stator and rotor bodypermanent magnet components from transient vibrations transmitted fromthe working end of the shaft. That is, the generator stator 58 ispositioned in axial alignment with the rotor body 50, on a side of therotor body 50 opposite the working end of the air tool and the magneticelements 51 are positioned accordingly. By positioning the stator 58 anddamped rotor magnets 51 remote from the working end of the air tool, ithas been found that the stator 58 and magnets 51 experience lessvibration.

Less vibration is experienced because working end vibrations, such asgrinding vibrations, diminish in amplitude due to the presence ofresisting forces such as clamping of the bearings upon the working endof the shaft, compressed air resistance, and friction between thesliding vanes 72 and the rotor body grooves and between the slidingvanes 72 and the inside of the cylinder wall.

Improved abrasion resistance and consequent increased life of the aircylinder 66 may be achieved by chrome plating the inside of the aircylinder 66. The chrome plate provides a tougher surface against whichthe air vanes 72 bear.

Improved efficiency and durability is also accomplished by potting thecore assembly 59 and circuit connections 60 and 61 in thermal conductivepotting material (not shown) and enclosing the potted components withina nonferrous stainless steel or titanium housing 62 and 64. The pottingprocedure forms a monolithic structure permitting no movement of parts,having no external wire leads and no discrete external electricalconnections other than the conductive halves of the generator housingseparated by a nonconductive plastic spacer 63 (FIG. 3). The structuralhomogeneity provided by this method of construction maximizes theruggedness of the device, protecting the otherwise sensitive core,copper windings and coil connections from the deleterious effects of theair motor environment.

Internal heat produced by current running through the coil wires isthermoconducted by the potting material from the windings to the metalhousing 62 (heat sink). The internal heat is further dissipated throughthe air flowing through the air inlet channel 65 (FIG. 3) entering theIAMG cylinder 66. That is, the stator 58 is positioned between thecompressed air inlet to the tool and the rotor body 50 such thatcompressed air flows across the stator 58 thereby conducting heat awayfrom the stator 58. The air flow is guided by the air inlet channel 65formed in the stator housing 62, non-conductive spacer 63 and rearstator housing 64.

Improved regulation of the magnetomotive drag coefficients and generatoroutput has been achieved by adjustment of the air gap between the rotormagnets 51 and the stator poles 57 behind the stator housing face 62A.This critical tolerance is maintained through the use of a rotor collar67 on the front (working end) of the rotor 50 to allow approximately0.007 inch between the magnetic end 50a of the rotor and the stainlesssteel or titanium positive generator face 62A, and by providing a statorhousing 62 with a wall thickness over the pole faces of approximately0.010 to about 0.035 inch. Adequate structural strength of the statorhousing 62 is ensured over the range of wall thicknesses by fabricatingthe stator housing 62 from, for example, titanium.

FIG. 6 is a transverse cutaway view of the interior 79 of an air toolshowing air inlet 69, wherein the airflow is shown by arrowheads withbroken tail lines throttle mechanism 70, block diagram of batterycharging and indicator LED circuit 71, generator stator 58, cantileverrotor 50 with air vanes 72, front bearing supports 73, power take-off(PTO) 74, battery cells 75, electrical contacts 76 and 77, and housing78. The improved motor-generator 68 provides means for conversion ofcompressed air to electromechanical energy within the air tool. The airtool may employ batteries 75 and charging circuit 71 so that it maystore excess electricity. The air tool is capable of being connected toa source of compressed air and utilizes a conventional air inlet 69 andthrottle-mechanism 70 located at the supply end of the unit. At theopposing end a port 74 is provided allowing access to the working end ofthe IAMG rotor shaft 50. The rotor shaft 50 is engageable through asplined coupling located at 74 which provides means for a power take off(PTO).

In a preferred embodiment, the air tool employs an internal circuithaving a full wave diode bridge integrated circuit for rectification ofthe alternating current to direct current, which rectifier is coupled toa battery charging circuit 71 with battery cells 75. The circuitry isconnected with conducting wires (not shown) such that the batteriesbecome charged while the IAMG is running. Further, in order to indicatethe proper functioning of the generating device, proper lubrication tothe sliding vanes 72 driving the IAMG and the momentary condition of thebattery cells 75, a circuit utilizing and LED 80 as a tricolored lightsource is provided. The LED is conspicuously embodied within the housingof the air tool in visible range of the operator. The LED's three colorsmay indicate green for generator "charging," amber for "lubrication low"and red for "battery discharging," or any other suitable arrangement.

One method of constructing the LED circuit is to utilize a conventionalbattery charging circuit 71 with the integration of a resistancetemperature detector (RTD) bridge circuit comprised of thermallysensitive resistors or thermistors. The bridge is electrically connectedto the battery charging circuit to create a monitoring path using afractional portion of the IAMG output as a drive current. One thermistor81 in the bridge may be directly implanted in the IAMG air cylinder wallor embedded into the inner housing of the air tool adjacent the aircylinder and having surface to surface contact with the cylinder outerwall 82. Appropriate electrical contacts between the thermistor and theLED circuit are provided. An identical thermistor may be planted at apoint where the temperature remains ambient with the compressed airentering the cylinder, such as adjacent the air inlet 69. Two otherresistors having the same ohmic resistance are included in the circuitto form the complete bridge. This arrangement will provide a comparativesample signal which will become representative of the difference betweena range of ambient temperatures and the cylinder wall temperature.

As the IAMG rotor and vanes begin to rotate, electrical energy forcescurrent to flow to the load (appliance or battery) through the chargingcircuit 71 and LED 80 causing it to emit light. The circuit is designedso that the tricolor LED will emit green at a nominal level of IAMGcurrent output. As the IAMG rotor vanes slide against the insidecylinder wall, heat due to friction from the sliding action is produced.As lubricating oil dissipates through operation of the air motor, moreheat will be generated than the air flowing through the cylinder is ableto carry away. Thermal conduction of the heat through the cylinder wallaffects the first thermistor 81 by changing its conductive resistance.The resistance of the thermistor 81 will then differ from the resistanceof the second thermistor associated with ambient air temperature,thereby causing an imbalance in the bridge and sending more (or less)current to the tricolor LED 80. The LED 80 is arranged to change colorfrom green to amber with more (or less) current available for itsconsumption. The LED color change becomes a visible indication of thelevel of the air motor lubrication.

A resistor in the monitor circuit is set so that the LED will emit greenat a temperature gradient known to be directly associated with normaltemperature conditions and yellow when the frictional temperaturereaches a point associated with a minimum acceptable level oflubrication. The tricolor LED may emit red when a load is drawing energyfrom the battery only and there is no generator current, such as whenthe air supply has been disconnected from the tool. This change incurrent is accomplished through transistor switching in the batterycharging circuit. The LED 80 thus becomes an integrated indicator of theperformance characteristics of the air tool.

The inventive thermistor-LED indicator circuit is applicable to knownair motor lubrication systems. Typical methods for lubricating the airmotor vanes include: (1) manual disconnection of the air tool from theair supply hose and the addition of droplets of oil to the tool airinlet with reconnection and running of the tool to force oil into theair motor; and (2) an in-line lubrication dispenser placed in the airline supply upstream of the air tool connection. In the first case, theLED indicator would indicate to the operator when to disconnect the tooland in the second case the indicator would indicate when it wasnecessary to add lubricant to the dispenser.

The interior 79 of the air tool shown in FIG. 6 may be housed in anonconductive compression resistant plastic enclosure or housing 78.Optionally, electrical contacts 76 and 77 may be affixed about the PTO74 end (working end) of the housing 78. The contacts 76, 77 are arrangedin similar fashion to a conventional battery pack and are electricallyconnected to the internal IAMG 68 and batteries 75. The electricalcontacts 76, 77 can be used as a source of power for additionalcomponents of an air tool.

The air tool may drive a plurality of conventional machine tool elementsincluding but not limited to: a collet, mandrel, spindle, socket drive,drill chuck, screw driver bit, disc, pad or other device, the purpose ofwhich is to perform a specific job. Various embodiments may also employone or more electronic devices (appliances) or circuits, referred toabove and described in greater detail herein, embodied with the tool toprovide enhanced performance objectives.

FIG. 7 shows a transverse cutaway view of the exterior housing 83 of theair tool. The interior 79 of the air tool shown in FIG. 6 is housed in acavity 84 in the air tool housing 83. The cavity 84 may include internalelectrical contacts 85 which mate with the contacts 76 shown in FIG. 6.A spindle shaft 86 extends beyond the housing 83 on the working end ofthe tool. The spindle shaft 86 is supported by bearings 87 and splinedon its internal end 88 to match the PTO splined coupling 74.

The interior 79 of the air tool shown in FIG. 6 is inserted into thecavity 84 of the housing 83 shown in FIG. 7 from an opening 89 at therear of the housing 83. The housing 83 is made of, for example, animpact resistant plastic such as glass reinforced Delrin. The interior79 of the tool shown in FIG. 6 may be keyed longitudinally to fit into achannel 90 located on the inside of the housing 83. The key and channel90 provides a means for precision alignment of the electrical contacts76, 85 and the PTO 74 and shaft 86. Once inserted into the housing 83,the interior 79 may be locked into position by a mechanical lockingmeans (not shown) located at the air inlet end of the tool so that whenthrottle lever 91 is actuated the IAMG 68 of the air tool begins torotate as a result of compressed air entering through the air inlet 69.

FIG. 8 shows the interior 79 of FIG. 6 inserted into the housing 83 toform a complete air tool.

FIGS. 8-10 show a tool light ring appliance 92 attached to the housingof the tool at the working end of the tool. The light ring appliance 92does not obstruct the view of the work by the operator of the tool fromvirtually any angle and provides a good source of illumination to thecentral focal point of the work and in an area radiating out 360 degreestherefrom.

In one embodiment, the air tool drives a tool such as a drill, grinder,polisher, screwdriver, nutrunner, ratchet or impact tool having theimproved and unique light ring appliance. The light ring appliance maybe formed integrally with the tool body which houses the tool's workingend components or may be threaded thereon. The appliance 92 isphysically unobstructive to the view of the work by the operator of thetool from virtually any angle. Because the need for improved lightingexists with other types of tools as well, the development of the lightring appliance is also intended by the inventor for applications beyondthe scope of air powered tools.

It is commonly known that wherever air tools and other non-electrictools are used, it is difficult to maintain adequate lighting on theworkpiece, particularly when working in closed areas. A discretelighting fixture such as a trouble light or flashlight can get in theway of the work, and requires a separate means of attachment or supportto properly illuminate the work. Furthermore, a discrete lightingfixture added to the tool body, such as a flexible gooseneck extension,may detract from the profile and esthetics of the tool and furtherreduce the mobility of the tool, in comparison to a tool having no suchfixture. It has also been found that a lighting fixture appending fromthe tool body and having only one lamp lights the work area from asingle angle thereby leaving a distracting shadow on the work area andsometimes fringe patterns in the lighted area. These undesirable factorssuppress interest in having embodied lighting fixtures associated withtools. The present invention therefore relates to improvements overexisting limited lighting means and to solutions to the problems raisedthereby.

Referring now to FIGS. 8 and 9, the invention includes a power sourcesuch as the IAMG 68 (a battery in a conventional cordless tool orhousehold current in an electrically driven tool). In each embodiment atlight ring appliance 92 is electrically connected to the power source.In one embodiment the light ring 92 is physically united with the toolcasing 93 in proximity to the working end of the tool and facing thework so as to properly facilitate placement of the light provided by thelight ring upon the work area. Removability is provided by a threadedattachment so that proper servicing of the tool, such as bearing andlamp replacement, can be accomplished.

The light ring 92 may comprise five basic components. A first componentis the base 94 which is a rigid structure made of, for example, anonconductive plastic and having a cylindrical ring configuration. Theoutside diameter of the base 94 is smaller than that of the tool housingend and is threaded at 94A so that it may be screwed into place within athreaded cavity at the working end of the tool. The base 94 providesfixturing and electrical conducting means for uniting the other lightring components to the tool housing and provides electrical contacts 95to provide power for the lamps 96. Alternatively, the base 94 may not beused and the electrical connections may be made directly to the ring97A.

The second component is an array of miniature incandescent lamps 96referred to generally as a multi-pak 97. Each lamp 96 in the array iselectrically connected to each other in parallel (circuit not shown) sothat if one lamp burns out the others will continue to illuminate. Eachlamp 96 is evenly spaced apart from the other in an encirclingarrangement as shown and held together in a uniform matrix by a moldedring shaped structure 97A made of, for example, nonconductive plasticand which encapsulates the bottom portion of each lamp's glass envelopeand the (connected) electrical leads from each bulb. Furthermore, themulti-pak's plastic encapsulant incorporates electrical contacts (notshown) having a negative and positive surface through which current issupplied to the lamp array circuitry from the base contacts 95. Thecontacts 95 may be positioned diametrically on the ring's outercircumference (recessed from the surface) or on the component's backside where surface-to-surface contact with the threaded base 94 is made(depending on which mode of conductance from the power source isutilized and depending upon the field polarity of the tool housing, ifconductive). Preferably, multi-pak array 97 has the same outer diameterand bore as the base 94 upon which it is positioned. The electricalcontacts 94 mate on their opposing ends (not shown) with currentcarrying conductors 98 embodied with the tool housing upon uniting theassemblage to the housing.

The third component is the reflector 99 which is a single solidstructure made of, for example, highly polished aluminum or vacuummetalized plastic and having on its face one recessed parabolic opening100 for each lamp 96 in the multi-pak 97. The reflector 99 preferablyhas the same outer diameter and bore as the threaded base 94 and themulti-pak 97 and includes apertures 101 through which the lamps 96protrude from its backside into each of the parabolic openings 100. Theapertures 101 in the reflector 99 are spaced according to the spacingand number of lamps 96 in the multi-pak 97 so that the reflector 99 fitsover the lamps 96 and contacts the surface of the multi-pak'sencapsulant structure.

A fourth component is a ring-shaped clear lens 102 which fits over thereflector face and is held into position with the reflector and themulti-pak by the fifth component, a threaded retainer ring 103. Theretainer ring 103 screws onto the threaded outer tool housing (insimilar fashion to a conventional flashlight assembly).

The working spindle of the tool 86 runs through the center bore of thebase 94, multi-pak 97, reflector 99 and lens 102. The spindle 86 may bethreaded to accept a standard locking collet 104 in which various toolbits may be inserted.

The encircling arrangement of the individual incandescent lamps 96provides radiant light in a direct line from each of the lamp'sfilaments, and light is also reflected from the multiple parabolicreflectors 100. Therefore, the tool bit and surface directly in front ofthe tool are brightly illuminated without shadows or obstructions andwith minimal fringe patterns.

The light ring appliance places light upon the work at a central focalpoint from the tool bit, radiating outward in 360 degree circularproximity, emanating from the tool body.

FIG. 10 shows another embodiment of the light ring 92 which uses clearacrylic or polycarbonate plastic medium to form a structural lightconducting component. In this embodiment, a keyless clear plastic lightconducting drill chuck accessory 108 includes a common and ordinarysteel jaw locking mechanism 106 and a wrench style square drive 105positioned in front of a light ring 92. The drill chuck accessory 108takes the position of the lens 102 shown in FIG. 9 to direct light tothe drilling surface. The face angle of the clear plastic chuck 104 maybe modified somewhat over one which is conventional so that light may befocused where the drill contacts the drilling surface. Furthermore, theexterior surface of the plastic cylinder forming the clear plastic chuck104, and the metal cylinder 107 in the center of the chuck, may bemetalized with aluminum or chromium thereby causing mirrored light toalso be reflected from the end of the chuck. The light ring assembly 92may be affixed to the air tool housing as an accessory or unitized withthe housing of the tool during manufacture. In use, light from the lightring source passes through the clear plastic portion of the drill chuckstructure and onto the workpiece.

FIG. 11 shows another embodiment which involves the integration of alight ring with a magnetic rotor and stator, components similar to thosepreviously described that comprise the generator of an IAMG, to form aunique tool illuminating accessory driven by a conventional airmotor ofan airtool. The partial transverse cutaway view in FIG. 11 shows anintegral light ring generator generally at 109 with a spindle 110 drivenby a tool rotor at 111. The spindle 110 is supported by a bearing 112and enclosed by a tool housing 113. A rotor structure segment 114contains the magnetic circuit elements 51 as shown in FIG. 1, and may beformed integrally with air moving fan blades 120 for cooling. Theairflow through the illuminating accessory is shown by arrows withbroken tail lines. The rotor structure segment 114 is affixed by setscrew or key way to the spindle 110 so that the magnet rotor structure114 spins with the spindle. A light ring reflector 115 is constructed ofthe alloy material utilized in the construction of the core of the IAMGstator, previously described. In addition to providing means for thereflection of light, the reflecting component 115 conducts the magneticflux alternations from the spinning magnets 51 through the coils at 116thereby causing emf to flow in the coil circuit and through the lampmatrix 117 thereby causing light. Cooling ports 118 may be provided inthe retaining ring 119 so that air can be drawn in for cooling the coils116 and light reflector 115. As an accessory for an air tool, such as ahigh speed die grinder, the integral light ring generator can easily bethreaded into position onto a conventional air tool.

Another embodiment of the integrated light ring which accomplishes thesame objective involves the use of light conducting fiber optic elementsarranged in an encircling array about the working end of the tool. Thisembodiment may utilize a single incandescent lamp which is opticallycoupled to converging ends of the fiber optic filaments from a pointabout the exterior housing or from within the enclosing body of thetool. The fiber optic light conductors may further be encapsulated in adurable opaque plastic vinyl in a molding process to form a flexibletool body boot. The molded vinyl boot would also serve as an aestheticshock resistant cover to protect both fiber optics and tool housing.

FIGS. 14A, 14B, 1SA, 15B, 15C, and 16 show an embodiment of a pneumatictool luminaire whereby illumination to the work surface is accomplishedby having a light source internally positioned inside the housing of thetool and whereby light is transmitted from the light source throughlight guides. The light source may be high intensity such asconventional quartz-halogen with tungsten filament, state of the artmetal halide (no filament), radio induction (no filament), or solidstate diode laser (for use in conjunction with optical line generationtechnology); each with respective driver circuitry constructed in axialalignment unity with the generator. An advantage of this embodiment isthat it maximizes isolation of high energy (high heat or radiological)light sources from the work environment. This isolation reduces, if notentirely eliminates, the chance exposure to harmful ultraviolet,infrared or radio emissions and the ignition hazard from an exposed arcof a broken lamp envelope. This embodiment also provides an efficientmethod for cooling the lamp, generator and power supply apparatusesusing compressed air entering the tool. Furthermore, this embodimenteliminates wires and electrical connections outside thegenerator-luminaire unit, thereby facilitating the use of the luminairewith conventional cast aluminum (conductive) housings. Light conductors,referred to as optical fibers and composed of glass or clear plastic,are used to conduct light from the internal light source to the exteriorworking end of the tool where converging ends of the optical fiberstransmit light to the work surface from a circular "light ring" array.

FIG. 14A shows an exploded perspective view of a generator stator coreand coils 59 connected to a single light source 420 enclosed by a fronthousing 62B, a transparent mid-section 63A and a removable end plate64A. FIG. 14B shows the components of FIG. 14A assembled in a completeunit designated as 58A.

Unlike the generator described in FIG. 3, which conducts electricity topositive and negative contacts at either of its exterior end plates, thestator coils 59 in FIG. 14A have a direct electrical connection to asingle high intensity lamp 420 through a ceramic connector 121containing appropriate electrical contacts, each positioned axially atthe rear of the generator stator 59. A glass envelope surrounding thebulb 420 is further housed in a transparent cylindrical section 63A madeof, for example, glass or polycarbon plastic. The section 63A replacesthe nonconductive ring 63 shown in FIG. 3. The transparent section 63Amay be partially silvered internally with reflective material to createa reflector 122 to concentrate light toward opposing points on thesection (these points will line up with "windows" in the tool body). Therear housing 64A is removably connected to facilitate lamp replacement.An air inlet channel 65 directs compressed air to the airmotor via thelength of the generator lamp assembly thereby effectively cooling theassembly during generator operation and lamp ignition. High intensitylamps such as halogen or metal halide arc depend on high temperaturesfor efficient cycling of reactive elements while producing intense lightoutput. The particular choices of material used, the dimension of thecylinder wall of the transparent section 63A and the surface area of thereflector 122 may vary as a means for regulating heat dissipation foroptimal operating temperature.

Referring now to FIG. 15A, the integral generator luminaire 58A is shownin position inside an air tool, in this case a die grinder, designatedas 410. The tool housing includes a number of "windows" or openings 123which are each aligned with transparent nonreflective portions ofsection 63A of the generator luminaire 58A, once in position within thetool. This arrangement allows light from the source 420 to pass throughthe tool body at a plurality of points.

As shown in FIG. 15B, protective tool body guard or "boot" 411 made ofshock resistant material, such as flexible vinyl, is used to protect thetool housing (made of, for example, cast aluminum) from abrasion and toprovide a better grip on the tool. In addition, the protective boot 411may incorporate optical fibers 124 which are encapsulated within theopaque plastic medium 125 during the formation process of the boot 411.The converging ends of the fiber optic filaments 124 may be optocoupledto 45 degree glass mirrors 126 which are also encapsulated (except forthe inward side). When the tool 410 is inserted into the boot 411 andthe "window" 123 aligns with the inward side of the mirror 126, thenlight from the high intensity source 420 is concentrated at the ends ofthe fiber optic elements 124. The opposite ends 124A of the opticalfibers, where the light emerges, are arranged in an encircling arrayabout the working end of the tool so that light is transmitted to thework surface.

Designated as 412 in FIG. 15C is a tool 410 incorporating a generatorluminaire 58A (FIG. 15A) as it would appear with the fiber optic boot411 covering the tool 410.

FIG. 16 shows a tool 413 incorporating the above-described principlesexcept that the optical fibers 124 are directly molded into a hardplastic tool housing or body 125A during the injection molding process,rather than being incorporated into a separate boot. FIG. 16 also showsa metal halide arc tube light source 127 (not filament) with the opticalfiber ends 124 bending directly toward the source (having no mirrors)and with opposite ends 124A emerging as a "light ring" at the workingend of the tool.

Also contemplated within the present invention is the use of a lamp or alight source that is external to the tool housing, in combination withoptical fibers and the tool cover or boot 411 of FIG. 15B or the toolhousing or body 125A of FIG. 16. FIG. 17 schematically shows an externallamp connected by optical fibers 124 to a tool covering or boot 411A.The boot 411A is similar to the boot 411 except that the optical fibersexit the boot 411A and are connected to the external lamp. The ends 124Aof the optical fibers 124 form a light ring similar to that in FIG. 15B.FIG. 18 schematically shows an external lamp arrangement similar to FIG.17 except that the optical fibers 124 are connected to a tool housing125B. The tool housing 125B is similar to the tool housing 125A shown inFIG. 16 except that the optical fibers 124 exit the tool housing 125Band are connected to an external light source. The ends of the opticalfibers 124A form a circular light ring similar to that shown in FIG. 16.In FIGS. 17 and 18, the optical fibers 124 that connect the externallight source to the tool cover 411A or tool housing 125B may be encasedin an air hose used to supply compressed air to the air tool or may bein a separate optical fiber carrier.

While the present invention has been disclosed with reference to certaindescribed embodiments, numerous changes, alterations and modificationsto the described embodiments are possible without departing from thespirit and scope of the invention, as defined in the appended claims andequivalents thereof.

What is claimed is:
 1. An air tool having a working end andcomprising:A. a tool housing; B. a compressed air inlet; and C. anintegrated air motor and electrical generator, for powering the tool andpositioned within the housing and including:1. a shaft mounted on abearing, for rotation within the housing;
 2. 2. a rotor body attached tothe shaft;3. a plurality of vanes connected to the rotor body;
 4. aplurality of magnetic elements disposed in the rotor body; and
 5. astator positioned within the housing coaxially with the rotor body, on aside of the rotor body opposite the working end of the air tool andbetween the compressed air inlet and the rotor body such that compressedair flows across the stator, wherein the stator interacts with themagnetic elements to generate electricity when the rotor body is rotatedby the compressed air.
 2. The air tool of claim 1, wherein the statorincludes a plurality of poles and a plurality of coils mounted onrespective poles wherein the poles are positioned equidistant from eachother, a number of the poles is the same as a number of the magneticelements and the poles are mounted in facing relationship to themagnetic elements so that axes of the poles are collinear with axes ofrespective magnetic elements.
 3. The air tool of claim 1, wherein thebearing on which the shaft is mounted is positioned on a side of therotor body adjacent the working end of the tool and the shaft does notextend beyond the opposite side of the rotor body.
 4. The air tool ofclaim 1, wherein the rotor body is made of a nonmagnetic material. 5.The air tool of claim 4, wherein the material is stainless steel.
 6. Theair tool of claim 4, wherein the material is one of carbon fiberreinforced thermoplastic and glass fiber reinforced thermoplastic. 7.The air tool of claim 1, wherein the magnetic elements are made of acompound that includes neodymium, iron and boron.
 8. The air tool ofclaim 3, further comprising a second bearing on which the shaft ismounted wherein the second bearing is positioned on the side of therotor body adjacent the working end of the tool.
 9. The air tool ofclaim 1, further comprising a second bearing on which the shaft issupported wherein the second bearing is disposed inside the stator. 10.The air tool of claim 2, wherein the poles are made of a magneticmaterial capable of conducting magnetic flux direction changefrequencies of at least 1000 hertz.
 11. The air tool of claim 10,wherein the magnetic material is one of Hiperco 50A Permendur 49 andAlloy
 4750. 12. The air tool of claim 2, wherein the coils include coilforms having inside wall thicknesses of about 0.010 inches.
 13. The airtool of claim 2, wherein the stator includes a stator housing andthermal conductive potting material and wherein the poles and coils arepotted in the thermal conductive potting material and enclosed by thestator housing.
 14. The air tool of claim 13, wherein the stator housingis made of one of nonmagnetic metal, plastic and a ceramic material. 15.The air tool of claim 13, wherein the stator housing includes an airinlet channel formed on an exterior surface thereof.
 16. The air tool ofclaim 1, wherein the stator includes a stator housing and furthercomprising a rotor collar disposed on the shaft on a side of the rotorbody adjacent the working end of the tool, for maintaining a desired gapbetween the side of the rotor body opposite the working end of the tooland the stator housing.
 17. The air tool of claim 16, wherein thedesired gap is about 0.007 inches and a thickness of the stator housingopposite the magnetic elements is about 0.010 to 0.035 inches.
 18. Theair tool of claim 1, further comprising a battery and a battery chargingcircuit connected to the stator.
 19. An air tool having a working endand comprising:A. a tool housing; B. a compressed air inlet; C. anintegrated air motor and electrical generator, for powering the tool andpositioned within the housing and including:1. a shaft mounted on abearing, for rotation within the housing;
 2. a rotor body attached tothe shaft;
 3. a plurality of vanes connected to the rotor body;
 4. aplurality of magnetic elements disposed in the rotor body;
 5. an aircylinder made of a nonmagnetic material and surrounding the plurality ofvanes; and
 6. a stator positioned within the housing coaxially with therotor body, wherein the stator interacts with the magnetic elements togenerate electricity when the rotor body is rotated by the compressedair; D. a battery charging circuit and a battery connected to thestator; and E. an indicating circuit connected to the battery chargingcircuit for indicating a battery charge condition, a battery dischargecondition, and a low lubrication condition.
 20. The air tool of claim19, wherein the indicating circuit includes a resistance temperaturedetector bridge comprising a thermistor disposed in the vicinity of theair cylinder and responsive to a temperature of a cylinder wall and athermistor responsive to a temperature of the compressed air.
 21. Theair tool of claim 20, wherein the indicating circuit includes a lightemitting diode that emits a first color when the integrated air motorand electrical generator is producing electricity and the temperature ofthe cylinder wall is within a normal range, a second color when thetemperature of the cylinder wall exceeds a normal range, and a thirdcolor when an electrical load is being drawn from the battery and theintegrated air motor and electrical generator is not producingelectricity.
 22. An air tool having a working end and comprising:A. atool housing; B. a compressed air inlet; C. an integrated air motor andelectrical generator, for powering the tool and positioned within thehousing and including:1. a shaft mounted on a bearing, for rotationwithin the housing;
 2. a rotor body attached to the shaft;
 3. aplurality of vanes connected to the rotor body;
 4. a plurality ofmagnetic elements disposed in the rotor body;
 5. an air cylinder made ofa nonmagnetic material and surrounding the plurality of vanes; and
 6. astator positioned within the housing coaxially with the rotor body, on aside of the rotor body opposite the working end of the air tool andbetween the compressed air inlet and the rotor body such that compressedair flows across the stator, wherein the stator interacts with themagnetic elements to generate electricity when the rotor body is rotatedby the compressed air; D. a battery charging circuit and a batteryconnected to the stator; and E. an indicating circuit connected to thebattery charging circuit for indicating a battery charge condition, abattery discharge condition, and a low lubrication condition.
 23. Theair tool of claim 1, further comprising a light ring assembly attachedto the tool housing to provide light at the working end of the tool..[.24. The air tool of claim 23, wherein the light ring assemblyincludes:a generally cylindrical retainer ring having open ends andconnected to the tool housing; an annular lens disposed in the retainerring at an end furthest from the tool housing; an annular reflectorhaving a plurality of openings formed therein and disposed adjacent thelens; and an annular ring having a plurality of lamps that are insertedin the openings of the annular reflector wherein the lamps areelectrically connected to the stator..]..[.25. The air tool of claim 24,wherein portions of the openings of the annular reflector areparaboloids..]..[.26. The air tool of claim 23 wherein the light ringassembly includes: a lamp electrically connected to the stator; and aplurality of optical fibers having first ends optically coupled to thelamp and second ends that terminate in a circular array at the workingend of the tool..]..[.27. The air tool of claim 26, wherein the toolhousing includes at least one opening adjacent the lamp..]..[.28. Theair tool of claim 23, wherein the light ring assembly includes: agenerally cylindrical retainer ring having open ends and connected tothe tool housing; a drill chuck having a transparent cover and connectedto the shaft at the working end of the tool; an annular reflector havinga plurality of openings formed therein and disposed adjacent the drillchuck; and an annular ring having a plurality of lamps that are insertedin the openings of the annular reflector wherein the lamps areelectrically connected to the stator; wherein the transparent cover ofthe drill chuck directs light from the lamps to a working surface..].29.An air tool having a working end and comprising:A. a tool housing; B. acompressed air inlet; C. an integrated air motor and electricalgenerator, for powering the tool and positioned within the housing andincluding:1. a shaft mounted on a bearing, for rotation within thehousing;
 2. a rotor body attached to the shaft;
 3. a plurality of vanesconnected to the rotor body;
 4. a plurality of magnetic elementsdisposed in the rotor body;
 5. an air cylinder made of a nonmagneticmaterial and surrounding the plurality of vanes; and
 6. a statorpositioned within the housing coaxially with the rotor body, on a sideof the rotor body opposite the working end of the air tool and betweenthe compressed air inlet and the rotor body such that compressed airflows across the stator, wherein the stator interacts with the magneticelements to generate electricity when the rotor body is rotated by thecompressed air; D. a battery charging circuit and a battery connected tothe stator; E. an indicating circuit connected to the battery chargingcircuit for indicating a battery charge condition, a battery dischargecondition, and a low lubrication condition; and F. a light ring assemblyattached to the tool housing to provide light at the working end of thetool.
 30. An air tool having a working end and comprising:A. a toolhousing; B. a compressed air inlet; C. an integrated air motor andelectrical generator, for powering the tool and positioned within thehousing and including:1. a shaft mounted on a bearing, for rotationwithin the housing;
 2. a rotor body attached to the shaft;
 3. aplurality of vanes connected to the rotor body;
 4. a plurality ofmagnetic elements disposed in the rotor body wherein the magneticelements are made of a compound that includes neodymium, iron and boron;5. an air cylinder made of a nonmagnetic material and surrounding theplurality of vanes; and
 6. a stator positioned within the housingcoaxially with the rotor body, on a side of the rotor body opposite theworking end of the air tool and between the compressed air inlet and therotor body such that compressed air flows across the stator, wherein thestator interacts with the magnetic elements to generate electricity whenthe rotor body is rotated by the compressed air; D. a battery chargingcircuit and a battery connected to the stator; E. an indicating circuitconnected to the battery charging circuit for indicating a batterycharge condition, a battery discharge condition, and a low lubricationcondition; and F. a light ring assembly attached to the tool housing toprovide light at the working end of the tool; G. wherein the statorincludes a plurality of poles and a plurality of coils mounted onrespective poles wherein the poles are positioned equidistant from eachother, a number of the poles is the same as a number of the magneticelements and the poles are mounted in facing relationship to themagnetic elements so that axes of the poles are collinear with axes ofrespective magnetic elements; and H. wherein the poles are made of oneof Hiperco 50A Permendur 49 and Alloy
 4750. .[.31. An illuminatingapparatus for a power tool having a spindle and a tool housing,comprising: a housing having first and second ends; a lens disposed atthe first end of the housing; a lamp disposed behind the lens; areflector surrounding the lamp and including a coil connected to thelamp; and a rotor including a magnetic element wherein the rotor isattachable to the spindle and is disposed adjacent the coil wherebyrotation of the rotor induces electromotive force in the coil; whereinthe second end of the housing includes a retaining ring for attachmentto the tool housing..]..[.32. The apparatus of claim 31, furthercomprising a plurality of lamps disposed behind the lens wherein thereflector includes a plurality of coils connected to the lamps and therotor includes a plurality of magnetic elements..]..[.33. The apparatusof claim 32, wherein the rotor includes air moving fan blades and thehousing includes at least one cooling port..]..[.34. The apparatus ofclaim 32, wherein the rotor is attachable to the spindle by one of a setscrew and a keyway..]..[.35. The apparatus of claim 32, wherein thereflector is made of a magnetic material capable of conducting magneticflux direction change frequencies of at least 1000 hertz..]..[.36. Theapparatus of claim 35, wherein the magnetic material is one of Hiperco50A Permendur 49 and Alloy 4750..]..[.37. The apparatus of claim 35,wherein the coils include coil formers having inside wall thicknesses ofabout 0.010 inches..]..[.38. The air tool of claim 27, furthercomprising an elastomeric, opaque tool cover that covers at least a partof the tool housing wherein a portion of each optical fiber isencapsulated in the tool cover..]..[.39. The air tool of claim 27,further comprising at least one mirror for optically coupling an opticalfiber to the lamp..]..[.40. The air tool of claim 26, wherein theplurality of optical fibers are encapsulated in the tool housing..].41.The air tool of claim 1, further comprising a plurality of dampingsleeves disposed between the rotor body and the plurality of magneticelements. .[.42. The air tool of claim 23, wherein the light ringassembly includes:a lamp located external to the tool housing; and aplurality of optical fibers having first ends optically coupled to thelamp and second ends that terminate in a circular array at the workingend of the tool..]..[.43. The air tool of claim 42, further comprisingan elastomeric, opaque tool cover that covers at least a part of thetool housing wherein a portion of each optical fiber is encapsulated inthe tool cover..]..[.44. The air tool of claim 42, wherein a portion ofeach of the plurality of optical fibers is encapsulated in the toolhousing..].